Preparation of motor fuels



Oct. Z4, 1939." w. M. STRATFORD PREPARATION 0F MOTOR FUELS OriginalFiled June 19, 1954 IN VEN TOR. 14.011. srRATfoRy www Patented Oct. 24,1939 UNITED STA'IES PATENT OFFICE PREPARATION F MOTOR FUELS William M.Stratford, Mamaroneck, N.

or to The Texas Company,

YI., assign- New York, N. Y., a

corporation of Delaware Substituted and reiiled for abandonedapplication Serial No.

21 Claims.

higher molecular weight hydrocarbons boiling /within the range ofcommercial gasoline.

The invention broadly contemplates a process in which normally. gaseoushydrocarbons, such as natural gas or gases produced in the pyrolyticdecomposition oi petroleum hydrocarbons, are very rapidly heated undersuperatmospheric pressure to a high cracking temperature to eiectconversion to a considerable 'degree into unsaturated hydrocarbons. Theresulting highly-heated mixture comprising unsaturated hydrocarbons andthis comparatively saturated unconverted gas is then quickly cooled orquenched by reducing the temperature'to one at which a desired com-.-bination or polymerization of the unsaturated compounds takes place.`The products of the cracking reaction are maintained at thistemperature While under superatmospheric pressure for a suitablewtime toeifect the formation of liquid hydrocarbons, such operation beingsometimes referred to hereinafter as a soaking of the products of thecracking reaction. The soaking treatment of the unconverted gas and theproducts of the high temperature decomposition may b ei'- fectedin thepresence of additional 'gases containing polymerizable constituents,introduced into the system for the further purpose of quenching .orlowering the temperature of the products of the high temperaturedecomposition.

As an additional or alternative feature, the invention includesemploying a liquid hydrocarbon as a quenching medium. This material mayadvantageously be a straight run naphtha which has a low anti-knockvalue.A In the course of its rapid elevation to high temperature duringthe quenching operation and the further subjection to the soakingtreatment at elevated temperatures and pressures, this naphtha may bereformed, that is, converted into anaphtha having a relatively highanti-knock value and may enter into desirable reactions with the gasesundergoing polymerization.

The invention also contemplates the separation and the resubjection tohigh temperature decomposition conditions of such portions of the chargeas may have been unconverted during the initial subjection to theseconditions. This may be accomplished either in the original heatingapparatus or in -a separate apparatus within which diiierent conditionsof temperature may be maintained.

yIn general, the treatmentis carried out in stages, the iirst stagebeing a high pressure, high temperature conversion of saturatedconstituents cf the original gases to unsaturates or olens, effected atvery short time of reaction, and arrested 731,245, June 19, cation June19, 1935, Serial 1934. This appli- No. 27,395

to prevent further reaction at the high temperatures of the initialstage to products of undesired character. 'Ihis initial stage is thenfollowed by.

a soaking period at a lower temperature and at longer time of reactionand under about the same pressure as is used in the rst or decompositionstage, wherein a polymerization of unsaturates to normally liquidproducts is eiected.

The operation of the process may be understood by referring to thefollowing description and the accompanying drawing. In the drawing:

The single figure is a more or less diagrammatic view, partly inelevation and partly in vertical section, illustrating apparatus whereinthe process of my invention may advantageously be carried out.

Referring to-the drawing, the numeral I0 represents a line through whichgaseous hydrocarbons are conducted from a storage, not shown, to a DumpI I, which may be of a type capable of delivering the hydrocarbons underpressures of from 500 pounds per square inch to as high as 2000 to 3000pounds per square inch o higher. The highly compressed gases pass fromthe pump H through a line I2 having alvalve I3, and then through aheating coil l5 positioned within a furnace I6. The preheated gasesdischarged from the coil I5 are delivered through a pipe I1, tted with avalve I8, and are discharged' into and to a point near the bottom of abath of molten material 2| situated within a reaction chamber 20. Thebath 2l may comprise any high melting point substance such as lead,cryolite or similar stable substance. The bath is-maintained at thedesired temperature by suitable means, asV for example,'by circulating aportion thereof through a heater 22 by means of a pump 23, or by othersuitable means such as electrical resistance heaters positioned in thebath. 'I'he hot products of the reaction which takes place within thereaction' chamber 20 are drawn-'oil through a line ZI'having valves 25and 26 and are delivered intoa.

soaking drum 28.

If the gases undergoing cracking in the chamber 20 are permitted toremain at the high temperatures maintained in the chamber 20 for too.long a time, polymerizing reactions may take place which areundesirable both from the standpoint of producing products of anundesired na'- ture and from the standpoint of. control of thepolymerizingreactlons which arevexothermic in character.v Consequently,the hot cracked gaseous products leaving the chamber 20 through the line24 are cooled or quenched to a considerably lower temperature at whichpolymerizing reactions of a more desirable character `may be effected,by means of some suitable cooling medium. For example a gaseous coolingmedium may be introduced into the line 24 through a line vals 3| havinga valve 32 and which is supplied with such gaseous cooling medium fromeither aline 30 o'r a line 99 or both. Alternatively or additionally,the quenching or cooling may be effected by delivering liquidhydrocarbons, preferably naphtha of comparatively low anti-knock value,into the line 24 in a manner set forth hereinbelow.

The soaking drum 28, which may be of any suitable type capable of'withstanding the temperatures and pressures employed in the operationof the process, is provided at its bottom with a drawoi line 34 havingvalves 35 and 36'and leading to a fractionating tower 31. Thefractionating tower is provided with cooling means 39 near the topthereof, and at the bottoml with a steam inlet pipe 40 having a valve4|, and serves as a means for separating gaseous hydrocarbons, togetherwith vapors of hydrocarbons boiling within a motor fuel range, fromhydrocarbons having higher boiling points. The former gases and vaporsare drawn H from the top of the fractionating. tower through a vaporline 52 having a valve 53 and are delivered into a cooling coil 54located in a condenser 55, where the normally liquid hydrocarbons aresubstantially condensed.

The bottom of the fractionating tower 31 is provided with a drawoff line50 through which high boiling hydrocarbons which collect as a residue inthe course of the fractionation operation are drawn oil to storage. Avalve is provided to control the flow through'the line 50. There is alsotted into an intermediate point in the fractionating tower structure adrawoff line 42, having a valve 43, and through which a liquidhydrocarbon fraction having a boiling point range somewhat higher thanthat of the usual motor fuel may be taken off.

The liquidhydrocarbons and gaseous hydrocarbons, which are drawn oilfrom the discharge side of the condenser coil 54, arev deliveredlthrough a line 51 having a valve 58 into a gas separator 60 whereinthey are substantially separated, the liquid hydrocarbons comprising afraction suitable for motor fuel being drawn off in a continuous streamfrom the bottom of the separator chamber through a line 6|, having aoatcontrolled valve 62. The gaseous hydrocarbons, on the other hand, aredrawn oil? from the top ot the separator through a line 63 having avalve 64 and passed either through a valved branch 65 :to a suitable gasstorage tank (not shown) or else recycled for further reaction.

'Ihe gases drawn oi from the top of the separator 60 will containhydrogen, methane and varying amounts of other gaseous hydrocarbons landit may or may not be desirable to recycle these gases. In any event,however, it is necessary to provide a ,means for eliminating from thesystem\hydrogen togetherwith any other gases which are not reacted toliquid productsA and which therefore tend to accumulate in the system,or an equivalent portion of the total gaseous products leavingtheseparator 60. This may be done by simply withdrawing a sumcient amountof Agas through the line 65 to prevent accumulato a hydrogen-eliminationstage |82v having a valved hydrogen vent |03 anda valved residue gasline |04, the latter communicating with the pipe 66 at a point betweenthe valve 68 and the compressor 69.

The hydrogen elimination stage |02 may comprise any suitable absorptionor separating system suitable for the purpose of separating the gasesand the hydrogen or hydrogen and methane and constituents oi highermolecular weight. Such systems are well known in the art and need not bedescribed here in detail. The hydrogen or mixture of hydrogen andmethane passes out of the system through the vent |03, whereas theconstituents of higher molecular weight which are'l capable of beingreacted to form valuable end products are returned through the line |04to the line 66.

Where the elimination step |02is so conducted as to remove methane aswell as hydrogen, the gases compressed by the pump 69 are deliveredthrough a line and a branch line 1I having a valve 12 to the line l2which supplies gases to the preheating coil I5.

Where, however, methane is not substantially eliminated in the stage|02, or where the gases returning through the line |04 to the line 66are considerablyJ more refractory in character than y bath 19 may besimilar to that comprising the bath 2| in the reaction vessel 20,` orelse it may comprise a substance which, because of the more stringenttemperature requirements in this, the second conversion stage, may havea higher melting point. The method of maintaining the temperature of thebath 19 may, with advantage, be the same as that described in connectionwith the rst conversion stage.

The hot products of the pyrolytic conversion which takes placein thereaction chamber 18,

are drawn oi through a line 80 having a valve 8|A and are delivered intothe line 24. Gaseous hydrocarbons for cooling may be introduced into theline 80 from the line 30 through a branch line 82 having a valve v83. Asindicated hereinabove, cooling of the hot conversion products inv thelines 24 and 80 may alternatively or additionally be effected byintroducing into these lines liquid hydrocarbons. These liquidhydrocarbons may either be products of the fractionation operation inthe tower 31, or a straight run naphtha obtained through a line 86 froman extraneous source. These materials may be injected into the lines 24and/orv 80 by means of pumps 44 and/or /81 having a common dischargeline 45 provided with valves 46 and 88 and manifolded to thelines 24 and80 by means of branch lines 41 and 84, having valves 48 and 85,respectively.

In a typical operation of the process in con-.

nection with the above described apparatus, a fraction of natural gas,or any other hydrocarbon gas containing substantial amounts of gaseousparanic hydrocarbons such as propane andA butane, is drawn from storageand delivered through the line l0 to the 'pump This pump discharges thehydrocarbons under a pressure of between 500 and 3600 pounds per squareinch a lower` temperature where they may ,be more' chamber 20,

or even higher into the heating coil I 5 o! the preheater I6 where thetemperature of the hydrocarbons is raised to about` 800 to 1100 F., thatis to say, a temperature just short ofo'ne at which rapid conversion ofsaturates to unsaturates is effected. v 1

Upon' leaving the coil I5, the heated hydrocarbons are conducted throughthe line I1 to a point near the bottom of the bath 2| situated withinthe reaction chamber 20. The bath 2| is preferably maintained at such atemperature that the hydrocarbons which are injected into it will beheated to a temperature of from 1200 to" 1500 F. or higher, say to 1700F. The variables controlling the heating of the hydrocarbons, includingthe depth of the lead bath, itsA temperature, and the charge rate of thegaseous hydrocarbons, are so controlled that. the hydrocarbons may beraised to the aforementioned temperature in the minimum space of time.

An important feature of thevinvention is the veryshort time during whichthe charging material is subjected to the higher decompositiontemperatures. The reason underlying this is that at the temperaturesemployed in the chamber 20 the saturated constituents undergo a veryrapid conversion to unsaturates or olefins capable of being polymerizedto normally liquid products. If such polymerization is allowed toproceed to any material extent at the high temperature employed for theproduction of olens in the the oleilns which are produced will tend topolymerize to products which are aromatic in character, such for exampleas benzol and, furthermore, the strongly exothermic polymerlzingAreactions which would thus be involved would make the reaction extremelydifllcult to control on account of the great liberation of heat at thehigh temperatures employed. It is therefore desirable that thepolymerizing reactions be prevented from being carried out to anymaterial extent at 'the hightemperatures employed for the conversion ofsaturates to unsaturates in the reaction chamber 20, and on the contraryto cause the polymerizin'g reactions to take place at easily controlledand where the resultant products will be more strongly oleflnic ornaphthenic in character. For these reasons, the reactions taking placein Ythe chamber 20 are quickly checked, permitting only lvery shorttimes of reaction of not more than one or two minutes' and preferably 15seconds ing the products of reaction to the desired poly-,- merizingtemperature by introducing thereto cool gaseous or vliquid hydrocarbonsof a suitablechar.- acter as0 described. a

This fquenching or cooling is preferably eifected as the lproducts of'the thermalconversion ef-v fectedf'in'the'reactionchamber 20 aredeliveredl through 'thje vapor line 24 into the polymerizing chambersoaking drum 28, for example by means of gaseous line III."A

These gaseous hydrocarbons may comprise natural gases or'nil refinerygases, preferably rich in olens, produced inl the' cracking ofhydrocarbon oils or gases, and may be obtained from, an external sourceor may comprise a portion or a fraction of the 'ultimate products of theentire process as' will be described more fully in connection with therest of thev drawing. The purpose of introducing such materials is notonly to veiect a lcooling or quenching of the hot products of' thegas-cracking operation but also to introducing either one or less, byquickly quench- Ahydrocarbons admitted through the effect a conversionof constituents of the gases thus introduced to normally liquidcompounds suitable for use as motor fuel.

` The temperature of the productsof the thermal decomposition may alsobe eiectively and rapidly hydrocarbon lwhichI is preferably saturated;in character, that is to say of lowanti-knock value, and which' isreadily susceptible to reformation by v thermal treatment into a productof only slightly diierent boiling point range but of higher anti-knockvalue. the liquid hydrocarbon of this character may be obtained eitherfrom a subsequent fractionation operation or from an extraneous sourceof straightrun naphtha. Provision is made for or both of these liquidhydrocarbons into the vapor line 24 bymanifolding thereto the lineSiwhich connects with an intermediatepoint in the fractionating tower31, and the linev 86 which connects an independent source of straightrun naphtha or other suitable liquid hydrocarbon.

In certain operations of the present invention, it may be founddesirable to preheat both the refinery gases as well as the liquidhydrocarbons to. an appropriate temperature above atmospheric so as tobring about a controlled reduction in temperature of theproducts ofdecomposition in the line 24 without unnecessarily cooling the same.

In the present example,`

jected to an appropriate soaking treatment at a Y,

predetermined temperature of, for example, from approximately 700tov1000 F., depending somewhat upon the character of the hydrocarbonsoperated upon.

Under the conditions maintained within the soaking chamber, furthercracking and polymerizing of the hydrocarbonspresent may be eiected,whereby desirable compounds useful as motorfuel are formed. vMorespecifically; these reactions maycomprise polymerization of gaseousunsaturates or olens to normally liquid materials, together, whereliquid hydrocarbons f such as naphtha have been introduced, with reandhaving boiling points within a motor fuel' boiling point range, as wellas interreactions between normally liquid products undergoing conversionand unsaturated materials undergoing 50 l formation of such liquidhydrocarbons toother liquid hydrocarbons of increased anti-knock valueoriginal gases charged are mixed either with cool- I er gases preferablycontaining a high percentage of unsaturated components or with liquidhydrocarbons which are substantially saturated in character. vantageousto use both gaseous and liquid hydrocarbons as cooling mediums.

The products which are formed in the soaking chamber 28 are drawn offthrough the line 34 and conducted into the fractionating tower 31, whichmay be maintained at the same pressure as the soaking drum or at aconsiderably lower pressure as desired. 'I'he fractionating tower 31 isso operated as to produce a vapor fraction consisting of normallygaseous hydrocarbons and hydro- In someoperations, it may be'found advcarbons boiling within the range of commercial gasoline, While free fromhigher boiling constituents, such as gas oil. This vapor fraction istaken off from the top'of the fractionating tower and is passed to thecondenser 55 where the normally liquid hydrocarbons are condensed. The

y mixture of condensate and gaseous hydrocarbons passing from thecooling coil is then separated in separator 60, the liquid hydrocarbonsbeing drawn i from the bottom .of the fractionating tower a liquidfraction which may have the character of gas oil or the like, and whichmay contain heavier constituents such as tar, unless provision has beenmade for removing tar prior to the entry of the vapors into the tower31, while from an intermediate point of the tower there may be taken offa liquid hydrocarbon fraction of the nature of a heavy naphtha or akerosene. This material may be used for cooling the products of thethermal decomposition by injection into the line 24.

The uncondensed gas which is separated from the liquid hydrocarbons inthe separator 68 comprises'principally the more refractory componentsand/or products of conversion of the original charging stock, as well assuch components of the refinery gases which were-charged into the line24 as a cooling medium, and which were'fnot affected `by the soaking'treatment to which they were subjected in the soaking drum 28.

As has been indicated hereinabove, it is preferred to treat theuncondensed gasto eliminate` therefrom hydrogen and/or hydrogen andmethane before recycling the remaining constituents.

which elimination is effected in thel stage IIII2,A

where the elimination stage is operated to remove hydrogen. and methaneand where the remaining gases are similar in character to thosecomprising the charging stock vintroduced through the line I0 theseresidual gases from which hydrogenand methane have been largelyseparated are preferably returned. to the inlet of the coil I5,` whereaswhen eliminated gases comprise principally hydrogen or in any eventwhere the residual gases are different in character from and morerefractory thany the charging stock introduced through the-line I8, theresidual gase are preferably delivered to the coil 14. i For example, inaccordance with the, latter alternative, the residual gases aredelivered to the pump 6,9, which delivers them under a pressure ofbetween 500 and 3000 pounds persquare inch, into the heating coil 1 4wherein their temperature is raised to 900 F.' or higher. 'Ihe heatedhydrocarbons are then immediately delivered through the line 16 toapoint near the bottom of the lead bath 19. The operating conditionsmaintained within the reaction chamber 18 are such that the gases arevery rapidly heated to a temperature which may be as high as 1800 F.

or higher.

order to limit the time of reaction, as soon as the gaseous products ofconversion leave the reaction chamber 18, and in that way to prevent anyhigh temperature soaking effect within the line 88, it is desirable thatthey be quickly cooled to a substantially lower temperature. This iseffected, as in the previous conversion stage in the process," byinjecting into the vapor line a suitable gaseous or liquid hydrocarbon.Provision for the use of a gaseous hydrocarbon is made by connecting theline 80 with the lines 30 and 99 by means of a branch line 82 having avalve through which such gases may be supplied. Similarly, a liquidhydrocarbon, for example from the fractionating; tower 31, or straightrun naphtha from an independent source, may be supplied 4to the line 80through lines 45 and 84 and/or lines 86 and 84,

respectively.

As has been indicated hereinabove, the gaseous hydrocarbon mediumemployed for quenching the products from the chambers 28 and 18 oreithermay comprise a fraction of the normally gaseousproducts produced in theprocess. However, the

gaseous or very low boiling hydrocarbon constituhydrocarbons may berecovered and employed as a cooling or quenching medium in the process,such means comprising principally a stabilizer I Ill to which the liquidproducts from the line 8l are delivered. The stabilizer IIO is ofconventional design, being provided with cooling means II I and heatingmeans II2 located respectively at the top and bottom thereof, and isinternally provided with the usual plates or trays for assistingfractionation. In the stabilizer III), the liquid hydrocarbons removedfrom the separator 60 are re-fralctionated to drive off dissolvedgaseous constituents such as butane and butylene.` The stabilized motorfuel product is Withdrawn from* the bottom ofthe stabilizer I IUthrougha valved line II3 and is delivered to storage, while the' separatedlight hydrocarbons passl through a valved line I I4 to a compressor II5which in turn supplied to the vline 24 and the line 80 or both asdesired.,

It will be apparent to those skilled in the art that various types ofheat exchange equipment may advantageously b e used in order toeffectheat economies in the operation of the process. In addition, theA`heating coils I5 and 14, which have been shown in independentpreheaters, may

' be placed within a common furnace structure and so positioned thereinthatthe desired working temperatures may be obtained. Economy inconstruction may also warrant the use of one lead bath reaction chamberinstead of the two which are shown in the drawing of the apparatus, ln

which case the proper heating of the two independent streams of gasesundergoing treatment may be effected by varying the length of the flowpath of the gases through the lead bath.

Moreover, While I have illustrated and described gas conversionoperations in which gases containing saturated constituents are firstpreheated in a heating coil to temperatures shortof active conversiontemperatures and are 'th'en passedv through a bath of molten materialwhere- 5o delivers them to the line 99 from which they are by they arevery rapidly heated to active conversion temperatures I may conduct thegas conversion reactions entirely in heated coils such as thoseillustrated in I and 14, thus dispensing with the chambers 20 and 18, orI may alternatively dispense with the preheating coils l5 and 'i4 andimpart all the heat necessary to effect con- 'version in the baths 2|and 19.' In anyevent, however, as has been indicated hereinabove, theheating ofthe largely saturated gases to conversion temperature is doneas rapidly as possible in order to insure very short times of contact`as set forth. y

It will be obvious to those skilled in the art that my invention issusceptible of considerable modification in detail and is therefore`-not to be construed as limited to the specific examples which havebeen set forth hereinabove by way of illustration but may variously bepracticed and embodied within the scope of the claims hereinafter made.

vThis application is a continuation in part of my co-pending applicationSerial No. 680,368 led July 14, 1933; and is substituted for myapplication Serial No. 731,245 iiled June19;-1934.

I claim:

1*. The process of converting normally gaseous parafnic hydrocarbonsinto normally liquid hydrocarbons suitable'for use as motor fuel or thelike, which comprises'compressing a gas containing a substantial amountof such gaseous parvaiiinic hydrocarbons to an elevated superatmosphericpressure, preheating the compressed gases to a temperature short of'active conversion thereof, thereafter substantially instantaneouslyheating the preheated gases to a conversion temperature sumcientlyelevated to eifect a rapid 'conversion of said gaseous paraftinichydrocarbons to unsaturated hydrocarbon gases capable of beingpolymerized to normally liquid products, arresting the progress of suchfurther reactions as may tend to take place at such elevated temperaturebyquickly cooling the resultant gaseous products to a substantiallylower but still elevated temperature adapted to promote polymerizationof said unsaturated hydrocarbon gases to normally liquid products, andmaintaining the gases at said lower temperature for a period of timerelatively long as-compared to the time of reactiony under the higherconversion temperature, without'substantially reducing the pressurethereupon, removing the resultant products and cooling them to recovernormally liquid products therefrom.

2. The process of converting normally gaseous parafnic hydrocarbons intonormally liquid hydrocarbons suitable for use as motor fuel or the like,which comprises compressing a gas containing a substantial amount ofsuch gaseous paraiiinic hydrocarbons to an elevated superatmospheriepressure, preheating the compressed gases to a temperature short ofactive conversion thereof, thereafter substantially instantaneouslyheatin g the preheated gases to a temperature sufficiently elevated toeffect a rapid conversion of said gaseous parafiinic hydrocarbons tounsaturated hydrocarbon gases capable of being polymerized tonormallyliquid products, arresting the progress ci such further. reactions asmay` tend to take place at such elevated temperature by quickly coolingthe resultant gaseous products to a temperature of from 700 to 1000 F.adapted to promote a polymerization of said unsaturated hydrocarbongases to normally liquid products, and maintaining the gases at suchpolymerizing temperature for a period of time relatively long `as tiallyreducing the pressure thereupon, removing the resultant products andcooling them to recover normally liquid products therefrom.

3. The process of converting normally gaseous paraiiinic hydrocarbonsinto normally liquid hydrocarbons suitable for use as motor fuel or thelike, which comprises compressing a gas containing a substantial amountof such gaseous paraiinic hydrocarbons to a pressure of from about 500to 3000 pounds per square inch, preheating the compressed gases to atemperature short of active conversion thereof, therefter substantiallyinstantaneously heating the preheated gases to a temperature of from1200 F. to 1700 F. and maintaining them at such temperature for a verybrief interval of time to effect a rapid conversion of said gaseousparaflinic hydrocarbons to unsaturated hydrocarbon gases capable ofbeing polymerized to normally liquid products. then quickly cooling theresultant gaseous products to a temperature of from 700`to 1000 F.adapted to promote a polymerization of said unsaturated hydrocarbongases to normally liquid products, and maintaining the gases at suchpolymerizing temperature for a period of time relatively long ascompared to the time o f reaction under the higher conversiontemperature, without substantially reducing the pressure thereupon,removing the resultant products and cooling them to recover normallyliquid products therefrom.

4. The process of converting normally gaseous parafnic hydrocarbons intonormally liquid hydrocarbons suitable for use as motor fuel or the like,.which comprises compressing a gas containing a substantial amount ofsuch gaseous parailinicuhydrocarbors to a pressure of from about 500 to3000 pounds per square inch. preheating the compressed gases to atemperature short of of active conversion thereof, thereaftersubstanthen quickly cooling the resultant gaseous products to atemperature of from 700 to 1000 F. adapted to promote a polymerizationof said unsaturated hydrocarbon gases to normally liquid products byintroducing directly into said resultant gaseous products a relativelycool hydrocarbon, and maintaining the gases at such polymerizingtemperature for a period of time relatively long as compared to the timeof reaction under the higher conversion temperature, withoutsubstantially reducing the pressure thereupon, removing the resultantproducts and cooling them to recover normally liquid products therefrom.

5. The process of converting normally gaseous paraiinic hydrocarbonsinto normally liquid hydrocarbons suitable for use as motor fuel or thelikeI which comprises compressing a gas containing a substantial amountof such gaseous paraiiinc hydrocarbons to a pressure of from about 500to 3000 pounds per square inch, preheating the compressed gases to atemperature short of active conversion thereof, thereafter substantiallyinstantaneously heating-the preheated gases to a temperature of from1200 F. to 1700 F. and maintaining them at such temperature for a verybrief interval of time to eifect a rapid conversion of said gaseousparafnic hydrocarbons to unsaturated hydrocarbon gas'escapable of beingpolymerized to normally liquid products, then4 15 upon, removing theresultant products and cooling them to recover normally liquid productstherefrom.

6. The processvof converting normally gaseous paralnic hydrocarbons intonormally liquid hydrocarbons suitable for use as motor fuel or the like,which comprises compressing a gas containing a substantial amount ofsuch gaseous parafnic hydrocarbons to a pressure of from about 500 to3000 pounds per square inch, preheating the compressed gases to atemperature short of active conversion thereof, thereafter substantiallyinstantaneously heating the preheated gases toa" temperature of from1200 F. to 1700 F. and maintaining them at such temperature for a verybrief intervalof time to effect a rapid conversion of said gaseousparaiiinic hydrocarbons .to unsaturated hydrocarbon gases capable ofbeing polymerized to normally liquid products, then quickly coolingtheresultant gaseous products to a temperature of from 700 to 1000 F.adapted to promote a polymerization of said unsaturated hydrocarbongases to normally liquid products by introducing directly into saidresultant gaseous products a stream of gases rich in gaseoust un-asaturated hydrocarbon constituentsand maintaining the gases at suchpolymerizing temperature for a period of time relatively long ascompared to the time of reaction under the higher conversiontemperature, without substantially reducingthe pressure thereupon,removing the rresultant products and cooling them to recover Y' normallyliquid products therefrom.

7. The process of converting normally gaseous `paraiinic hydrocarbonsinto normally liquid hydrocarbons suitable foruse as motor fuel or thelike, which comprises preheating agas contain ing a substantial amountof such gaseous parafnic hydrocarbons to a temperature short of activeconversion, thereof, substantially instantaneously heating the preheatedgases to a conversion temperature suflicientlyelevated to effect a rapidconversion of said gaseous paraflinic hydrocarbons to unsaturatedhydrocarbon gases c apable of being polymerized to normally liquid 150products in a rst conversion stage, and subjecting resultant unsaturatedhydrocarbon gases to av substantially lower but still elevatedtemperature and superatmosphericv pressure in aA soaking stage topromote polymerization'-of said unsaturated hydrocarbon gases tonormally liquid products, removing the resultant products,-

cooling them and recovering normally liquid products therefrom,subjecting a portion of the remaining gaseous products to a higherconversion temperature than that rst mentioned to eiect a conversionof4K gaseous paraffin hydrocarbons to unsaturated hydrocarbon gases in asecond and separate conversion stage, and introducing resultant gaseousproducts from said second conversion stage into said soaking stage.

Y awr/,421

8. The process of converting normally gaseous paraiiinic hydrocarbonsinto normally liquid hy drocarbons suitable for use as motor fuel or thelike, which comprises preheating a gas containing a substantial amountof such gaseous paraifinic hydrocarbons to a temperature short of activeconversion thereof, substantially instantaneously heating the preheatedgases to a conversion temperature sufficiently elevated to effectV arapid conversion of said gaseous paraflinic hydrocarbons to unsaturatedhydrocarbon gases capable of being polymerized to normally liquidproducts in a first conversion stage, and subjecting resultantunsaturated hydrocarbon gases to a substantially lower but stillelevated temperature and superatmospheric pressure in a soaking stage topromote polymerization of said un.

' freed gaseous products to a conversion temperature higher than thatfirst mentioned in a second and separate conversion stage, andintroducing the resultant gaseous products .into said soaking stage.

9. The process of converting normally gaseous hydrocarbons consistingsubstantially entirely of paraiiinic constituents into normally liquidhydrocarbons suitable for use as motor fuel or the like, which comprisescompressing such a gas to an elevated superatmospheric pressure,preheating the compressed gas to a temperature short of activeconversion thereof, substantially instantly heating the preheated gasesto a conversion temperature suiiciently elevated to effect a-rapidconversion of said gaseous paraflinic hydrocarbons to unsaturatedhydrocarbon gases capable of being polymerized to normally liquidproducts, arresting the progress of vsuch further reactions as may bepromoted at such elevated temperature by quickly cooling the resultantgaseous products to a substantially lower but still-elevated temperatureadapted to promote polymerization of said unsaturated hydrocarbon gasesto normally liquid products, and maintaining the gases at suchpolymerizing temperature in a soaking stage for a period of timerelativelylong as comd pared to the time of reaction under the higherconversion temperature, without substantially reducing the pressurethereupon, removing the resultant products, cooling them and recoveringnormally liquid products therefrom,'fractionating' the normally liquidproducts thereby recovered Iing the compressed gas to a temperatureshort of active conversion thereof, substantially instantly heating thecompressed gases to a conversiontemperature sufficiently elevated toeiectja rapid conversion of said gaseous parainic hydrocar-V bons .tounsaturated hydrocarbon gases capable of being polymerized to normallyliquid products,

arresting the progress of such further reactions as may be promotedatsuch elevated temperature by quickly cooling the resultant gaseousprodmoved to the hot products passing stage for use carbons 'to arated'hydrocarbons, then rapidly cooling to a temperature of between 700and 1000 F., and soaking the thus 'cooled conversion products in thistemperature range and under a pressure of bons thus-obtained for furtherconversion treatment to the preheating tsep.

12. Thev process of converting normally gaseous.`

s; paraflnic' hydrocarbons into liquid hydrocarbons,

u the preheated gases thethus preheated: gases y'in y y 'zoneto atemperature of between 15.00 and 1800" which comprises compressingy thegaseous hydrocarbons to'a pressureof between 500 and 3000.I

pounds` per square inch; preheatingthe compressed-gas to a temperatureof from 800 to 1100 AF.^,`substantially instantaneously heating.'

to a temperature of froml 1200 to1700 F. to rapidly '/convert`thernintoun'- saturated hydrocarbons, then a-temperature'of between 700 an'df1000F., and

and 3000 pounds per square inch, preheating the compressed n to 1100 F.;substantially instantaneously heating a y separate heating F.,f.qucklycooling 'the sa'm'e betweenA 700 0 into the I'aforementioned salfrin'gystage. l

13.v They process of converting gases,containingparazflinic"constituentsy pounds per square.,V in

mnic gases to a temperaturev of from 8005 to 1100 and 17'00"F. torapidly convert the gaseouspara-l I ing the mixture at this gasesto'atemperatu're off'from, 900

ture therewith Iof a suitable quantity of the compressed gases rich inolefinic constituents, soaktemperature and under a per square inch,preheating theparaffinic gases to a temperature of from 800 to 1100 F.,substantially instantaneously heating the preheated gases to atemperature of between 1200 and to convert the parafiinic constituentshydrocarbons, compressing a portion of the latter to a pressure 'of persquare inch, preheating the compressed gases to a temperature of between900 and 1000 F., substantially instantaneously heating the thuspreheated gases in a separate heating zone to a temperature of between1500 and 1800 F., then rapidly cooling them to a temperature of between700 and 1000 F. by admixture therewith of -a suitable rquantity ofrelatively cool compressed gases rich in olenic hydrocarbons andsubjecting the mixture to the soaking operation as aforesaid.

15. The process of forming a motor fuel havbetween 500 and 3000 poundsing a high anti-knock v'alue which comprises compressing normallygaseous parafnic hydrocarbons to a pressure of from 500 to 3000 poundsper square inch, preheating the compressed gases to l to 1100 F.,substantially instantaneously heating the' preheated a temperature offrom 800 gases toa temperature of from 1200" to 1'700.c F. to convertthe parailnic `hydrocarbons intol unsaturated hydrocarbons, quicklycooling the products of conversionto a temperature of from 700 to 1000F. by admixture therewith having a low anti-knock value, soaking theresultant mixture at this temperature and under a pressure of from.500.to..3000 pounds per square inch to'effect a conversion-olf;unsaturated compounds and naphthaA into normally liquid hydror l to@temperature of and `10'00 F., land introducing them carbons havingrelatively high anti-knock value,

1100. yF., substantially Ainstantaneously heating the preheated gasesina separate heating zone f to a ytemperatureof ybetween 1500"v and 1800F.

to convert `paraiinic vhydrocarbons into unsaturated hydrocarbons,quickly cooling the thus heatved gases'to a temperature "of from 700 to,1000 F; by admixture therewithof a naphtha, and introducing the mixtureinto the aforementioned soaking stage.

16. The process of tunning a. motor fuel of high of a naphtha anti-knockvalue which comprises separately compressing normally gaseous parainichydrocarbons and normally gaseous oleiiinic hydrocarbons to a pressureof from 500 to 3000 pounds per square inch, preheating the paraflinichydrocarbon gases to a temperature of between 800 and 1100 F.,substantially instantaneously heating the thus preheated gases to atemperature of between 1200 and 1700 F. to -rapidly convert paranichydrocarbons into unsaturated hydrocarbons, then quickly cooling thesehydrocarbons to a temperature of between '700 and 1000 F. by admixturetherewith of suitable quantities of both the compressed olenic gases anda normally liquid hydrocarbon havinga low anti-knock value, soaking theresultant mixture under a y pressure of from 500 to 3000 'pounds persquare inch to leffect a conversion of unsaturated compounds and saidliquid 'hydrocarbons into normally liquid hydrocarbons of relativelyhigh anti-knock value, and separating the resultant normally liquidhydrocarbons from any remaining gaseous hydrocarbons.

' 17. The lprocess for pyrolytically converting normally gaseousparaflinic hydrocarbons into liquid hydrocarbons which comprisescompressing the gaseous hydrocarbons to an elevated superatmosphericpressure, preheating the compressed gas to a temperature short of activeconversion, substantially instantaneously heating the preheated gases toa temperature sufliciently elevated to rapidly convert them intounsaturated hydrocarbons, then rapidly cooling to a temperature adaptedto promote polymerization of unsaturated hydrocarbons, and soaking thethus cooled conversion products at polymerization temperature and underelevated superatmospheric pressure to form liquid hydrocarbons, thenseparating the liquid hydrocarbons from any *remaining gaseoushydrocarbons and recycling the latter for further conversion treatmentto the preheating step.

18. The process of formmg a motor fuel .of

high anti-knock value which comprises separately compressing normallygaseous paramnic hydrocarbons and normally gaseous oleflnic hydrocarbonsto a pressure of between 2000 and 3000 pounds per square inch,preheating the paraiinic hydrocarbon gases to a temperature -of between800 and 900 F., substantially linstantaneously heating the thuspreheated gases to a temperaturev of between 1200 and 1500 F,to

' convert the parafiinic hydrocarbons into unsaturated hydrocarbons,then suddenly cooling these hydrocarbons to a temperature of between 900and 1000 F. by admixture therewith oisuitable quantities of both` thecompressed olenic gases and a normally liquid hydrocarbon having a lowanti-knock value, soaking the` resultant mixture undera pressure o fbetween 2000 and 3000 pounds per square inch to effect the conversionof.` theunsaturated compounds and the liquid hydrocarbons into liquidhydrocarbons 4 having high anti-knock values, separating the liquidhydrocarbons from any remaining gaseous.

hydrocarbons, withdrawing the latter, compress- -ing them to a pressureof betyeen 2000 and 3000 pounds persquare inch, preheating thecompressed gases to a temperature of between 900 and 1000* F.,substantially instantaneously heating the preheated gases in a separateheating to a temperature short vof active conversion zone toatemperature of between 1500? and 1800" F. to 'convert' any parailinichydrocarbons into r unsaturated hydrocarbons, cooling the `thus heatedgases rapidly -to a temperature in they range of between 900 and 1000?F- by. admixing therewith suitable quantities of thegcompressed olenichydrocarbon gases and a normally liquid hydrocarbon having a lowanti-knock'value, and combining the resultant mixture withf'thehydrocarbon mixture in the soaking stage of the 10 process.

y19. The process for pyrolytically v,converting normally gaseousparaflinic hydrocarbons into liquid; hydrocarbons which comprisescompressing the gaseous hydrocarbons to an elevated su- 5 peratmosphericpressure, preheating the compressed gas to a temperature short of activeconversion, substantially instantaneously heating the preheated gases toa temperaturev sufficiently elevatedto rapidly convert them intounsaturat- 20 ed hydrocarbons, then rapidly cooling to a temperatureadapted to promote polymerization, and soaking the thus cooledconversion products at polymerization temperature and under elevatedsuperatmospheric pressure to form liquid hydrocarbons, separating theliquid hydrocarbons from any remaining gaseousv hydrocarbons,withdrawing the latter, subjecting gases thus obtained in a separatezone to conditions effective to produce polymerization thereof, and com-30 bining gases so treated with the hydrocarbons 1n the soaking stage ofthe process to undergo polymerization. y

20. The process of converting normally gaseous hydrocarbons intonormally liquid hydrocarbons 35 suitable for use as motor fuel or thelike, which comprises 'compressing a gascontaining parafflnichydrocarbons to an elevated superatmospheric pressure, preheating thecompressed gas carbons suitable for use as motor fuel, which 55comprises preheating hydrocarbon gas predominating in parainichydrocarbons to a temperature short of activeconversion thereof while atan elevated superatmospheric pressure, substantially instantaneouslyheating said preheated gases toi a suiiciently elevated temperaturewhile under elevated superatmospheric pressurev to rapidly convertparainic hydrocarbons to olenichydrocarbons, cooling the resultantgaseousVN 'Y products,- polymerizing4 olenic hydrocarbons thus producedand cooled while under elevated superatmospheric pressure to lliquidhydrocarbons containing motor fuel, and separating and recovering motorfuel from the products of M polymerization.

WILLIAM M. STRATFORD.

